My textbook says
Molarity is dependent on temperature, whereas molality is not.
I'm aware of the definitions of both molarity and molality, but consider this scenario:
A solution of $\ce{NaCl}$ in $\ce{H2O}$ is heated. Eventually, all the water will escape and I will be left with only $\ce{NaCl}$ crystals. At the end, there is no solvent to even measure the concentration of what was once a solution. In this case, how does the argument "molality is independent of temperature" still hold true?